| 摘要 |
PURPOSE:To approximately simultaneously erasing and recording by being equipped with a magnetic field switching means to be able to switch the magnetic field given to a recording medium to two positive and negative directions and a light source to generate a pair of erasing beams to invert the magnetization a width direction half only in a track. CONSTITUTION:An erasing beam pair 28 generated by a laser array for erasing is placed at the position preceding to a recording reproducing beam 38, and further, when one side of only of erasing beams 29 and 30 lights up, the pair is dislocated and arranged so that only the right and left half of a track can be magnetized and inverted. When information 31 recorded previously is the binary information of the magnetization in a lower direction and an intermediate condition, the magnetic field formed by an electromagnet is directed upward, only the erasing beam 30 is caused to combine and light up, and thus, previous information is erased, a recording beam 39 is modulated and the new information is recorded. When the information recorded previously is recorded by the magnetization of the upper direction and the intermediate condition, the direction of the magnetic field and the erasing beam are switched and rewriting is executed in the same way earlier. Thus, erasing and recording can be executed approximately simultaneously. |
